Known methods of making a cluster pack begin with a wide stream of randomly-oriented containers standing on a transport plane of a transporter with their container axes oriented vertically. Lane dividers then convert the wide container stream into single-track container streams. In further method steps, the containers that are to be formed into a cluster pack are divided off from the single-lane container streams. The required number of containers is combined to form a consolidated container group in which the containers bear against one another by a plurality of circumferential surfaces, or contact surfaces. The containers of each container group are then bound to form a compact and stable cluster pack.
A number of ways are known for binding the containers together. One way is to use shrink films. Another way is to encompass the containers with a band.
One disadvantage of using bands is that, when a container is first removed from a banded cluster pack, the band can no longer securely hold the remaining containers. This is true even if the band is never cut. Even without cutting the band, removing a container will disrupt the integrity of the cluster pack.
Another problem that arises is that when such cluster packs are being transported, vibrations or mechanical disturbances can cause cylindrical articles, such as cans, bottles or containers, to slide into the gap in the neighboring row. This behavior, which is often called “nesting,” can be prevented by maintaining the bands under very high tension.
Another known method for assembling packs of bottles, uses rotary starwheels on both sides of a path to press bottle necks into clamps on flat carriers. A band or sheath can then encompass the resulting pack of bottles.
It is also known to apply adhesive to containers in narrow areas or rows. Adjacent areas, which are not provided with adhesive, then allow the pack to be gripped for carrying. In these cluster packs, containers stick to one another at the adhesive sites. Also known is providing containers with an adhesive and arranging a shrink film around the containers.
In the case of tall, long containers, a large overlapping length of film is required to reasonably fill a shrink gap. This leads to a high material consumption and thus to considerable film costs. Additionally, long film ends at the sides laminate very poorly to one another. In a shrink tunnel, they shrink unevenly. This results in a wrinkly appearance. Such an appearance can create an impression of substandard quality and thus diminish sales.
The containers of a cluster pack usually have a container code, such as a barcode or a QR code, that can be read by a suitable reader. The container code contains information for the retailer. It is useful for each container to have such a code so that individual containers can be removed from the cluster pack and sold one at a time.
In some cases, one may wish to sell the cluster as a whole. In that case it is useful to have a cluster code on the shrink film that is arranged around the cluster pack so that a code-reader can detect the price of the cluster pack.
A problem that can arise when there is both a cluster code and a container code is that the reader may read the wrong code. Instead of reading the code for the cluster pack, the reader ends up reading the code for a container. This can result in a cluster pack being sold for the price of a container. Although this may be a boon for a consumer, it is a considerable disadvantage for the retailer.
It is also known to provide the cluster pack with a carrying handle that is connected as a film strap to some of the PET bottles or even to the encompassing shrink film to form a carrying loop. This enables the cluster to be carried by one hand. However, because a cluster can be quite heavy, the film strap can press into the carrying hand and quickly inflict considerable pain. Thus, even when a strap is provided, a consumer will often lift the cluster pack by its bottom. This defeats the purpose of the film strap, namely that of having a second hand free.